Pearl, the birthstone for June, is among the most timeless,
classic and treasured of all gems. Throughout history,
these noble gems have been associated with wisdom, wealth,
purity, romance and mystery. The ancient Egyptians were
buried with them. In Rome, pearls were considered the
ultimate symbol of wealth and status. The Greeks prized
them for their beauty and association with love and
marriage. Medieval knights wore them in battle as a
talisman against injury. And during the Renaissance,
some European countries banned all but nobility from
the right to wear them.

It's hard to believe that such a luscious, beautiful
gem comes from such humble origins. A natural pearl
starts out as a grain of sand or microscopic worm that
works its way into an oyster and cannot be expelled.
To protect its soft body from this irritant, the oyster
secretes a smooth, hard crystalline substance called
nacre. Layer upon layer of nacre coats the foreign object
and hardens, ultimately forming a pearl. In general,
the thicker the nacre, the richer the "glow"
of the pearl - which can greatly enhance its value.

Although early pearl gathering depended on divers braving
the oceans' depths to retrieve these treasures, the
vast majority of pearls today are grown, or cultured,
on pearl farms by surgically inserting a small shell
bead, or nucleus, into the mantle of an oyster.

Even though pearls are harvested en masse on pearl
farms, producing a quality pearl is an extremely rare
event. It is estimated that half of all nucleated oysters
do not survive - and of those that do, only 20% bear
marketable pearls.

Pearls - the recommended gift for couples celebrating
their third and 30th wedding anniversaries - are cultured
in a variety of sizes, shapes, colors and kinds:

Akoya pearls are the classic round pearls found in
most quality pearl jewelry. They are mainly grown in
the waters off Japan. They come in a range of hues,
including white, cream, pink and peach.
White South Sea pearls are grown in Australia, Indonesia,
the Philippines and other areas of the South Pacific
and are prized for their large size.
Tahitian pearls, grown in French Polynesia, can be very
large and come in a range of natural colors from gray
to black to green to purple. Because of their large
size and unique dark colors, they command very high
prices.
Mabe pearls, grown in Japan, Indonesia, French Polynesia
and Australia, are usually flat-backed because they
form against the inside shell of the oyster rather than
within the oyster's body. They are often used in earrings
and rings.
Freshwater pearls are grown in bays, lakes and rivers
primarily in Japan, China and the United States. They
are often irregularly shaped, of various colors, and
are less lustrous than saltwater cultured pearls Ehence,
they are substantially cheaper.
When shopping for pearls, the five factors that determine
value are luster (surface brilliance); surface cleanliness
(absence of spots, bumps or cracks); shape (generally,
the rounder the pearl, the higher its value); color
(pearls come in virtually every hue of the rainbow,
and a few others, too); and size (the average pearl
sold is 7-7.5 millimeters, but these gems can be as
small as 1 millimeter or as large as 20 millimeters).
High-quality pearl strands will feature pearls well-matched
in these characteristics.

Because pearls are soft, ranking only 2.5-4.5 on the
Mohs scale for hardness, they require special care.
Natural oils from the skin, as well as hair spray, lotions
and cosmetics, can dull their luster. Like other jewelry,
they should be cleaned with a soft damp cloth and stored
in cloth or cotton away from other jewelry to prevent
scratching. Also, avoid allowing your pearl to come
in contact with harsh chemicals, which can erode its
surface. And if worn frequently, pearl necklaces should
be brought to a jeweler once a year for re-stringing
to prevent strand breakage.